The present invention relates generally to an apparatus for supporting a patient; and more particularly relates to an air mattress replacement system for use upon a bedframe to provide comfort and/or therapeutic support to a bedridden patient.
It is well known to use either an air-fluidized or low air loss bed to provide comfort and therapy to individuals who are bedridden for long periods of time and unable to move themselves. See, e.g., U.S. Pat. No. 4,483,029 issued Nov. 20, 1984 to Paul (use of air-fluidized bed) and U.S. Pat. No. 4,949,413 issued Aug. 21, 1990 to Goodwin (use of low air loss bed). Generally, a patient supported upon an air-fluidized bed is positioned so as to "float" upon the cushion created when air is continuously directed upward through a layer of silicone beads or other fluidizable material positioned beneath the patient. Air fluidized therapy is particularly suited for use in the treatment of patients who suffer from severe burns or the most severe bedsores. Low air loss therapy, on the other hand, has been demonstrated to reduce the occurrence of pressure ulcers caused by the loss of capillary circulation, and has been shown to be a most effective aid in the treatment of bedsores. Low air loss therapy helps maintain a patient's peripheral circulation by distributing the patient's weight over multiple cushions filled with air. The even distribution of pressure on the skin tends to limit capillary closure, thereby helping maintain tissue viability around bony prominences such as the sacrum and the heels. Independent movement of the surface of the low air loss cushions with respect to one another helps to decrease shear on a patient's skin. The fabric itself used in the cushions forming the sleep surface may be selected so as to also help decrease friction between the patient and the bed. In addition, because the fabric may be air permeable, air that escapes from the cushions typically is able to flow beneath and around the patient, which helps promote drying of the patient's skin.
One commercially available low air loss bed is the FLEXICAIR Low Air Loss Therapy unit, available from the Hill-Rom Company, Batesville, Ind. The FLEXICAIR bed is a five-zone, 21-cushion low airloss surface built upon a Hill-Rom Century Series hospital bed frame. It is a static low air loss product, meaning that once the air zones are adjusted to a patient's particular height and weight, the pressures within the bags of that bed are maintained fairly constant during use absent some further readjustment, and some air is allowed to escape from one or more bags during use, either through small perforations in the bags, or through the bag fabric itself while an air source continuously replaces such air and maintains a fairly constant pressure.
Recent advances in low air loss bed technology, however, have led to the introduction of more advanced products such as the EFFICA bed, also commercially available from the Hill-Rom Company. The EFFICA bed combines the effectiveness of a static low air loss bed with the additional patient therapy modes of turning, percussion and vibration.
Historically, there has been an ongoing search by care providers for effective, low cost therapeutic devices that has led them away from the use of foam mattresses, pads and bubble mats, and toward low air loss beds, mattress replacements, and overlays. Further, although both the FLEXICAIR and the EFFICA beds have been met with acceptance by doctors, nurses, and other healthcare providers, a seemingly never ending search by caregivers for effective therapies at lower costs has led to additional requests for an advanced frameless technology. Hospitals and clinics in particular have led the way toward use of mattress replacements and overlays by looking for a way to utilize bed flames they already own in conjunction with the latest, most effective air mattress technology available.
The primary difference between a mattress replacement and an overlay is that an overlay is typically used on top of an existing bed frame and mattress, while a mattress replacement is used in conjunction with a bed frame as a substitute for an existing mattress. One commercially available air mattress system is the ACCUCAIR Low Air Loss overlay unit available from the Hill-Rom Company, Batesville, Ind.